Mechanically held contactor with manual release



MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE Filed Jan. 3, 1966 6 Sheets-Sheet 1 I E I o INVENTORS day/v 6" //I/?M/7/V/Y AND P 40 l/. #691 AC Dec. 12, 1967 A HERRMANN ET AL 3,358,252

MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE 6 Sheets-Sheet 2 Filed Jan. 5, 1966 arr/g 4-7;

Dec. 12, 1967 A HERRMANN ETAL 3,358,252

MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE Filed Jan. 3, 1966 6 Sheets-Sheet 3 Dec. 12, 1967 J. A. HERRMANN ET AL 3,353,252

MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE 6 Sheets-Sheet 4 I Filed Jan. 5, 1966 J. A. HERRMANN ET AL 3,358,252

MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE 5, 1966 6 Sheets-Sheet 5 Dec. 12, 1967 Filed Jan.

Dec. 12, 1967 J. A. HERRMANN ET AL 3,353,252

MECHANICALLY HELD CONTACTOR WITH MANUAL RELEASE' Filed Jan. 5, 1966 6 Sheets-Sheet 6 50 zviz/a United States Patent Office 3,358,252 MECHANEUALLY HELD @QNTAETOR WHTH MANUAL RELEASE John A. Herrmann, Grosse Pointe Farms, and Andrew J. Kraliir, Detroit, Mich, assignors to ll-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed .lan. 3, 1966, Ser. No. 518,366 Claims. (Cl. 335-170) The instant invention relates to mechanical latches utilized with contactors and in particular relates to latches of this type which may be released both electrically and manually.

Copending U.S. patent application Ser, No. 266,252 filed Mar. 19, 1963, now Patent 3,235,687, assigned to the assignee of the instant invention, entitled Electro Magnetically Releasable Contactor Latch with F. W. Kussy et al. as inventors, discloses a mechanical contactor latch unit which is so constructed that the latch thereof is biased to latching position and is momentarily operated to unlatching position by electro-magnetic means to permit opening of the contactor. While a mechanical latch of this type has many advantages over an electrical latch, under certain operating conditions mechanical latches of the prior art are not capable of achieving desired operating results.

More particularly an electro-magnetically releasable contactor latch of the type provided by the prior art cannot be unlatched if there is an outage of control power, if there is a failure in the release magnet coil or control circuit, or if there is a total power failure where inrush currents may be excessive at the instant power is restored.

Accordingly, it is a primary object of the instant invention to provide manually operable means for unlatching an e1ectro-magnetically releasable contactor latch.

Another object is to provide an especially compact, reliable and inexpensive construction for an electro-magnetically releasable contactor latch having provisions for manual release.

Briefly, the contactor latch unit of the instant invention comprises an operating coil for moving the mechanical latch to unlatching position and a single pole double throw switch whose position is a function of the latch position. With the contactor in open position the contact carrier thereof is positioned to mechanically maintain the latch in its open position and under these circumstances the latch unit switch is positioned so that there is a closed switch section in series with the contactor operating coil and the normally open start control.

Closing the start control energizes the contactor operating coil thereby closing the contactor contacts and operating the contact carrier to a position wherein it no longer maintains the latch in open position. The contactor latch unit biasing means is then free to operate the latch to latching position. Upon this occurrence the contactor latch unit switch is operated so that the portion thereof in series with the contactor coil is now open and a portion thereof in series with the mechanical latch unit operating coil is now closed. This last portion or" the switch and the contactor latch unit coil are in series with a normally open stop control. Momentary operation of the stop control energizes the coil of the contactor latch unit thereby operating the mechanical latch to open position and permitting the biasing springs of the contactor to operate the latter to open circuit position.

A manually operable member is provided in a readily accessible position clear of current carrying elements. This member includes an extension which is operably engageable with the mechanical latch for unlatching thereof upon a loss of control power.

Additional objects and novel features of this invention 3,353,252 Patented Dec. 12, 1967 shall become readily apparent after reading the following description of the accompanying drawings in which:

FlGURE 1 is a side elevation showing a mechanical contactor latch unit, constructed in accordance with the teachings of the instant invention, mounted for cooperation with a contactor.

FIGURE 2 is a front elevation of the latch unit.

FIGURE 3 is a plan view of the latch unit.

FIGURE 4 is an elevation looking at the front of the internal housing section showing this housing section and the elements mounted thereto.

FIGURE 5 is a plan view of the elements of FIGURE 4 looking at the direction of arrows 55 of FIGURE 4.

FIGURE 6 is an elevation looking at the rear of the front housing section showing this housing section and the elements mounted thereto.

FIGURE 7 is a cross section taken through line 77 of FIGURE 6 looking in the direction of arrows 7-7 and showing all of the elements of the mechanical latch unit viewable at this point.

FIGURES 8 and 9 are side elevations looking in the direction of arrows 88 of FIGURE 2 with certain elements sectioned to more clearly reveal other elements. In FIGURE 8 the contactor latch unit is unlatched while in FIGURE 9 the unit is in latching position.

FIGURE 10 is an exploded perspective illustrating the main sub-assemblies of the contactor latch unit.

FIGURE 11 is an exploded perspective of the internal housing section and the elements mounted thereto.

FIGURE 12 is a fragmentary cross section illustrating a modified construction.

FIGURE 13 is a schematic showing the electrical coordination between the contactor latch unit and a contactor.

Now referring to the figures. Mechanical contactor latch unit 28 is provided with a housing constructed of internal layer 21 sandwiched between external front and back layers 22, 23. Four screws 24 secure back housing layer 23 to internal layer 21 while screws and 126 received by threaded apertures 25a, 26a of terminal members 25 and 26, respectively, mount front housing layer 22 to internal layer 21.

Terminal members 25 and 26 are riveted in fixed position to internal layer 21 with terminal portions 25b and 26b of members 25 and 26, respectively, projecting outwardly from opposite ends of the latch unit housing. Upper portion 260 of member 26 positioned internal of housing 21-23, carries switch contact 27. Portion 250 of terminal member 25, positioned internal of housing 21- 23, is provided with V-notch 29 which constitutes a pivot point for switch arm 30. Terminal member portion 250 extends between the spaced longitudinal sections of switch arm 30 with pivot end 3'1 of arm 30 received in V-notch 29 while the other end of switch arm 30 carries contacts 27a and 28a on opposite sides thereof. As will hereafter become apparent, movable contact 27a is operable into and out of engagement with stationary contact 27 while movable contact 28a is operable into and out of engagement with the stationary contact 28. Contact 23 is mounted to strap 32 extending from encapsulated double coil assembly 44.

Switch arm 30 is operated by overcenter spring 33 which is a coiled member in compression. One end of spring 33 is positioned by projection 34a of insulating slide 34 while the other end of spring 33 is positioned between the spaced longitudinal sections of switch arm 30 and engages lug 30a thereof. As will become apparent, slide 34 is operable from the position shown in FIGURE 9 in a direction away from rear housing layer 23 to a position (FIG. 8) wherein spring '33 is overcenter and thereby operates switch arm 30 so that contact 28a disengages contact 28 and contact 27a engages contact 27.

Slide 34 is journalled for movement within aperture 35 (FIGURE 11) of internal housing layer 21 and is prevented from cocking by bearing against guide lug 99 and slot 93 (FIGURE 4) of internal housing layer 21 cooperating with complementary formations 99a, 98a, respectively, of slide 34. Slide 34 also extends between the spaced longitudinally extending sections of switch arm 30. The rear of slide 34 is notched at 34b to receive upward extension 36a of mounting member 36.

The lower portion of member 36 is provided with two outward extensions 36b, 36b which are disposed within recesses 37, 37 formed through the cooperation of the internal and rear housing layers 21, 23 so as to provide a pivotal mounting for member 36. Member 36 is also provided with lanced ear 40 which constitutes a mechanical latch extending rearwardly through aperture 45 in rear housing layer 23. Compression spring 39 (FIG- UR'E interposed between slide 34 and the rear of guide lug 99, biases latch 40 outward of housing 21-23 toward its latching position.

Rivets 41 fixedly secure armature 42 to pivoted member 36. As best seen in FIGURE 7, armature 42 is of U- shaped cross-section and as seen in the other figures, the armature faces are extremely elongated with the long dimension extending transverse to the pivotal axis of member 36. Armature 42 is positioned so as to be attracted by the electromagnet consisting of yoke 43 and double winding assembly 44. Yoke 43 is a U-shaped member of substantially the same size as armature 42 with each coil of winding assembly 4 4 encompassing a different arm of yoke 43 and also encompassing the gaps between armature 42 and yoke 43. Rivets 47 (FIGURE 2) fixedly secure yoke 43 to front housing layer 22. Yoke 43 and winding assembly 4 4 are mounted within front housing layer 22 with the winding of assembly 44 being connected in electrical series from conducting strap 32 to terminal member 46 which extends through front housing layer 22 forward thereof.

It is noted that both armature 42 and yoke 43 are of single piece construction rather than being of laminated construction. It is also noted that the V-shaped air gaps which exist between armature 42 and yoke 43 when Winding 44 and 45 are deenergized are not completely closed when the windings of coil assembly 44 is energized because member 36 abuts an appropriately positioned formation of internal housing layer 21. Because of this it is not necessary to build in a fixed air gap.

As seen in FIGURE 1, mechanical latch unit 20 of this invention is operated in conjunction with contactor d of a type fully described in the Cataldo et al. application, Ser. No. 189,915, filed April 24, 1962, now Patent 3,324,- 431, entitled Electrical Device, and assigned to the assignee of the instant invention. In the aforesaid application there is shown a holding interlock unit 300 mounted to spaced terminals 1%, 1% (FIGURE 2 of the instant application) at the line end of contactor 100.

As seen in the electrical schematic of FIGURE 13, mechanical latch unit 2% is electrically connected in circuit as follows. With latch 40 in the open or unlatched position it occupies in FIGURE 8 there is a series circuit between line L']l and line L-2 which extends from terminal 2'51) through switch arm 30, switch contact 27, terminal 261), operating coil 210 of contactor 100 and normally open start control 111. Under these conditions, if start control 11 1 is closed, contactor coil 210 will be energized so that the contact carrier 1417 (FIGURE 9) of contactor 100 will move downward to a position below latch 40 thereby enabling spring 39 to move latch 40 to its latching position illustrated in FIGURE 9 wherein latch 40 is positioned to block upward movement of contact carrier 107.

Spring 39 in moving the upper portions and member 3 6 in a clockwise direction,

of armature 42 or to the right 4 with respect to FIGURE 9, also moves slide 34 to the rear. This positions spring 33 to operate switch arm 30 in a counterclockwise direction about its pivot end 31, as viewed in FIGURE 3, thereby bringing contact 28a into engagement with contact 28.

Now the circuit between lines L-l and L-Z is as follows. From terminal 25b through switch arm so contact 28, the windings of mechanical latch coil assembly 44 and terminal 46 to normally open stop control 108. Under these conditions the closing of stop control 108 is effective to cause energization of mechanical latch winding assembly 44, thereby generating a magnetic flux of sufficient magnitude so that armature 42 is attracted to yoke 43. This moves latch 40 to the left of contact carrier 107 when viewed in FIGURE 9 thereby permitting the return springs (not shown) of contactor 100 to open contactor res.

As seen in FIGURE 1, even though mechanical latch unit 20 is considerably taller than holding interlock 3% of Patent 3,324,431, mechanical latch 20 is still short enough to fit within enclosure cover 110 of Patent 3,324,431.

Contactor latch unit 20 also includes manually operable latch release member slidably mounted to front housing section 22 with inwardly projecting formations 22a, 22b in section 22 cooperating with slots 81a, 81b, respectively, in member 80 to guide movement of member 80. Movement of member 80 is also guided by housing formation 220 which extends into recess 81c of member 89. Downward extension 83 at the rear of member 80 is positioned to the rear of upward extension 36a of mounting member 36 and is engageable therewith upon forward movement of member 80.

As clearly seen in FIGURE 3, member 80 includes main plate-like portion 82 accessible at the top of unit 20 for manual operation to release latch 40. In order to manually release latch 40 member 80 is operated in the forward direction (indicated by the arrow embossed on portion 82) from its position of FIGURE 9 to that of FIGURE 8. During this movement downward extension 83 engages mounting member extension 36a so that mounting member 36 pivots in a counterclockwise direction to the position of FIGURE 8 wherein latch 40 is moved to the left of contact carrier 107 thereby permitting contact carrier 107 to move to its open position under the influence of the opertaing springs (not shown) of contactor 100. Extension 36a engages the rear of slide 34 moving the latter forward and in so doing changing the position of spring 33 so that contact arm 30 changes position separating contacts 28, 28a and bringing contacts 27, 27a into engagement so that contactor 100 may be operated upon the next closing of start control 111 (FIG- URE 13).

The embodiment of FIGURE 12 is provided with a manually operable depressable member for manual release of latch 40. Depressable member 90 is provided with sloping cam surface 91 positioned to engage the upper end of mounting member extension 36a upon movement of member 91) in the direction of arrow A. As cam surface 91 moves downward and engages extension 36a the latter is moved to the left with respect to FIGURE 12 thereby carrying mounting member 36 to the left, moving latch 40 to release position and at the same time bringing about the closing of contacts 27, 27a. It should now be obvious that cooperating formations (not shown) of member 90 and latch unit housing limit outward movement of member 90.

Thus, it is seen that the instant invention provides a novel mechanical latch unit for contactors with the latch not only being releasable by electromagnetic means but also being manually releasable to permit operation when there is a loss of control power and/ or when trouble develops in the stopping circuit.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A mechanical latch unit for a contactor, said unit comprising a housing, an electro-magnet having a movable armature, first means including said armature and a latching part extending through a wall of said housing external thereof for maintaining contactor contacts in engagement, biasing means urging said first means to a first position wherein said latching part is in latching position for maintaining contactor contacts in engagement, said electro-magnet upon energization thereof operating said first means to a second position wherein said latching part is in unlatching position for permitting contactor contacts to be opened, a switch means within said housing in engagement with said first means for operation thereby as said first means moves between said first and said second positions, said switch means having a first section which is open when said first means is in said first position and closed when said first means is in said second position, said switch means having a second section which is closed when said first means is in said first position and open when said first means is in said second position, said electro-magnet including an operating coil, and second means within said housing connecting said coil in circuit with one of said switch means sections such that energizing current for said coil passes through said switch means, third means mounted to said housing for manually operating said latching part to said unlatching position, said third means including a first and a second portion, said first portion accessible for manual operation externally of said housing from normal position to a releasing position, said second portion engaging said first means at a point remote from said latching part to operate the first means to said second position upon operation of said first portion to said releasing position.

2. The unit of claim 1 in which the second section of said switch means constitutes said one of said switch means sections.

3. The unit of claim 1 in which said latching part moves inwardly with respect to said housing in moving to said unlatching position.

4. The unit of claim 1 in which the third means is guided for sliding movement generally in the direction of movement of said latching part in moving between said latching and said unlatching positions.

5. The unit of claim 1 in which the second portion includes a cam formation which engages said first means and operates the latter to said second position upon operation of said first portion to said releasing position.

6. The unit of claim 5 in which third means is guided for sliding movement transverse to the direction of movement of said latching part in moving between said latching and said unlatching positions.

7. The unit of claim 6 in which the third means is depressed for operation to said releasing position.

8. The unit of claim 1 in which the biasing means is a compression spring bearing against said housing and an insulated movable part of said switch means.

9. The unit of claim 8 in which said switch means also includes a pivotally mounted switch arm and a contact operating spring in compression bearing against said arm and said insulated movable part.

10. The unit of claim 9 in which said switch arm is an elongated member pivoted at one end thereof, contact means mounted at the other end of said switch arm, said operating spring engaging said switch arm in the vicinity of said other end, said operating spring and said switch arm constituting portions of an overcenter toggle for operating said switch means with a snap action.

References Cited UNITED STATES PATENTS 2,525,846 10/1950 Wilson 335-470 3,209,102 9/1965 Boley 335-170 3,235,687 2/1966 Kussy et al 335170 3,315,190 4/1967 Mouis 335-173 BERNARD A. GILHEANY, Primary Examiner.

H. BROOME. Assistant Examiner. 

1. A MECHANICAL LATCH UNIT FOR A CONTACTOR, SAID UNIT COMPRISING A HOUSING, AN ELECTRO-MAGNET HAVING A MOVABLE ARMATURE, FIRST MEANS INCLUDING SAID ARMATURE AND A LATCHING PART EXTENDING THROUGH A WALL OF SAID HOUSING EXTERNAL THEREOF FOR MAINTAINING CONTACTOR CONTACTS IN ENGAGEMENT, BIASING MEANS URGING SAID FIRST MEANS TO A FIRST POSITION WHEREIN SAID LATCHING PART IS IN LATCHING POSITION FOR MAINTAINING CONTACTOR CONTACTS IN ENGAGEMENT, SAID ELECTRO-MAGNET UPON ENERGIZATION THEREOF OPERATING SAID FIRST MEANS TO A SECOND POSITION WHEREIN SAID LATCHING PART IS IN UNLATCHING POSITION FOR PERMITTING CONTACTOR CONTACTS TO BE OPENED, A SWITCH MEANS WITHIN SAID HOUSING IN ENGAGEMENT WITH SAID FIRST MEANS FOR OPERATION THEREBY AS SAID FIRST MEANS MOVES BETWEEN SAID FIRST AND SAID SECOND POSITIONS, SAID SWITCH MEANS HAVING A FIRST SECTION WHICH IS OPEN WHEN SAID FIRST MEANS IS IN SAID FIRST POSITION AND CLOSED WHEN SAID FIRST MEANS IS IN SAID SECOND POSITION, SAID SWITCH MEANS HAVING A SECOND SECTION WHICH IS CLOSED WHEN SAID FIRST MEANS IS IN SAID FIRST POSITION AND OPEN WHEN SAID FIRST MEANS IS IN SAID SECOND POSITION, SAID ELECTRO-MAGNET INCLUDING AN OPERATING COIL, AND SECOND MEANS WITHIN SAID HOUSING CONNECTING SAID COIL IN CIRCUIT WITH ONE OF SAID SWITCH MEANS SECTIONS SUCH THAT ENERGIZING CURRENT FOR SAID COIL PASSES THROUGH SAID SWITCH MEANS, 